let a = {
    name : 'tom'
}
let b = [1,2,3]
console.log(b instanceof Object); //true
console.log(instance_of(b,Object)); //true
console.log(instance_of(b,Function)); //false
 console.log(b.__proto__ === Array.prototype); //true
console.log(Object.prototype.__proto__ );//null
 function instance_of(left,right) {
     let leftVal = left.__proto__
     let righttVal = right.prototype
     while(true){
         if(leftVal === null) return false
         if(leftVal === righttVal) return true
         leftVal = leftVal.__proto__
     }
 }